The invention relates to an electric gas discharge lamp comprising a discharge vessel which is mounted on a stem or frame said frame and discharge vessel being accommodated in an outer envelope, the frame having a free end portion on which resilient elements are mounted which are in resilient contact with the inner wall of the outer envelope.
A gas discharge lamp of the type described is known from U.S. Pat. No. 2,240,333.
The resilient elements of tape or strip-shaped metal ensure that the discharge vessel remains positioned with respect to the outer envelope and that shocks and vibrations to which the lamp is exposed are transferred to the discharge vessel to a minimum extent and that the stem or frame is in compliance with thermal expansion.
In such lamps the outer envelope often breaks prematurely. It has been found that this breakage is often due to the presence of scratches in the inner wall of the outer envelope. When the outer envelope breaks, the discharge vessel with its metal lead-throughs and connections is exposed to the ambient air and the lifetime of the lamp is reduced, notably by oxidation. The thermal control of the lamp is then also considerably affected. A reduced light output may be the result. Furthermore, unwanted ultraviolet radiation may emerge from the discharge vessel.